Christer Sinderby , Thiago Bassi , Ling Liu , Daijiro Takahashi , Songqiao Liu , Ewan Goligher , Jennifer Beck
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引用次数: 0
Abstract
Background
A mode of ventilation is introduced that integrates CO2 clearance (“Through-Flow”, TF) with Continuous Neurally Adjusted Ventiator Assist (cNAVA). The new mode, referred to as “TF+cNAVA”, is a unidirectional flow system where inspiratory lumen(s) within an ET tube delivers fresh gas at the carina and the main ET tube lumen allows overflow of fresh gas to provide assist in proportion to the electrical activity of the diaphragm (Edi). The aim was to evaluate the effect of TF+cNAVA on breathing parameters during respiratory provocations, its reproducibility, and its sustainability. Conventional NAVA was the comparison.
Methods
46 rabbits were studied in three protocols: (i) NAVA vs. TF+cNAVA in open chest with added dead space, acute lung injury (ALI), single lung ventilation, and vagotomy (n = 8); (ii) Eight repeated comparisons, to demonstrate reproducibility (n = 8); (iii) ALI rabbits (n = 30) randomized to either NAVA or TF+cNAVA (6 h). Parameters studied: Edi, tidal volume (VT), breathing frequency (FB), minute ventilation (VE), transpulmonary pressure (PL), and PaCO2.
Results
With added provocations, NAVA showed an increase in Edi, VT, FB, PL and VE from baseline by 43 % (P = 0.004). TF+cNAVA significantly reduced Edi, VT, FB, PL, and VE from baseline, by 73 % (P < 0.001). In NAVA vs. TF+cNAVA crossover, TF+cNAVA consistently reached apneic levels for Edi, VT, FB, PL, and VE. During 6 h of TF+cNAVA, PaCO2, Edi, VT, FB, PL, and VE were significantly reduced compared to NAVA and baseline.
Conclusion
TF+cNAVA unloads respiratory muscles and suppresses respiratory drive, while reducing lung distending pressure.
期刊介绍:
Respiratory Physiology & Neurobiology (RESPNB) publishes original articles and invited reviews concerning physiology and pathophysiology of respiration in its broadest sense.
Although a special focus is on topics in neurobiology, high quality papers in respiratory molecular and cellular biology are also welcome, as are high-quality papers in traditional areas, such as:
-Mechanics of breathing-
Gas exchange and acid-base balance-
Respiration at rest and exercise-
Respiration in unusual conditions, like high or low pressure or changes of temperature, low ambient oxygen-
Embryonic and adult respiration-
Comparative respiratory physiology.
Papers on clinical aspects, original methods, as well as theoretical papers are also considered as long as they foster the understanding of respiratory physiology and pathophysiology.